SHARE

Autumn purple ash takes time to establish itself, but worth wait

The autumn purple ash we purchased and planted this year is a little lopsided as far as the lateral limbs go. It has a nice arrangement of limbs at the top, but it only has three lower limbs that all go in the same direction.

I was wondering what would happen if I pruned two of the lower branches. Would that even up the appearance of the tree? (Maybe I should take off all three?) Does the growth of the tree distribute branches in all directions or should I help it out by trimming the limbs? What time or year should I do it? Now or in the spring?

— Paulette

I think you’ll be very happy with the autumn purple ash. They really are lovely trees.

I wouldn’t do any pruning right now even though the tree is a little lopsided. As young as the tree is, I think it’s important that you keep all of the limbs now. They are where the plant is storing water and carbohydrates to use to begin growth next spring. Cutting those limbs off deprives the tree of those reserves.

Those limbs also will put on leaves, which is where photosynthesis occurs, producing more carbohydrates for the tree to use in growth and development. That’s important in getting a young tree such as yours re-established in the yard as quickly as possible.

You’ll eventually cut those limbs off, just not right away. Leave the tree alone for now, making sure you do a good job watering and feeding.

While the tree is establishing itself in your yard, it won’t grow very much, only a couple of inches or so a year, and the foliage will be smaller than normal and somewhat sparse. That’s nothing to worry about. This is a normal process the tree must undergo after it’s planted.

The entire process will last anywhere from six months to three years, depending on the size of the tree (the bigger it is, the longer it usually takes), how well the tree was transplanted, and the care you give it once it’s in your yard. I would say the average is about one year.

Once the tree has re-established itself in your yard and begun to produce good growth (12 inches or more per year) and has normal-sized, dense foliage, then you can start to think about cutting off those limbs.

With lower limbs, we usually do a process called “limbing up.” This involves removing the lower branches on a tree to get the canopy higher off the ground so you’re not knocking your head on a low branch.

People often think that a low limb will grow higher off the ground as the tree grows. That’s not true. If the center of that branch is 5 feet above the ground, it will still be 5 feet from the ground in 20 years, it will just be thicker and heavier and more in the way. (And probably leave a bigger knot when you hit your head on it!)

When you start limbing up the tree, do it gradually. It can be stressful to the tree if you remove too much branch tissue at one time. If there are three lower limbs you want to remove, you might take one or two the first year and then the remaining one or two the next year.

Going slow gives the tree a chance to recover from the loss of the branch and start healing. In time, you may even decide to remove some of those upper branches if that’s what will give you the tree form you’re looking for.

The time of the year to do this pruning really isn’t that important, but I like to do it best in March. The tree is still bare of foliage so I can see the branches clearly and make better decisions about what to prune and where to prune.